Electrolytic rectifier.



W. MORRISON. ELBGTROLYTIG RBCTIFIER.

APPLICATION FILED 118.29, 1912.

1,023,092. Patentd Apr, 9,

gil/3mm l. 'n /`I c a y j 4 j/2% fw ent, Ser. No. 587 ,129, tiled October 14, 1910,

y rod or plate of bismuth alloyed with a rela- -WILLIAM MORRISON, OF IJIES M'I'NES, IOWA.

ELECTROLYTIC 'QECFIFIER.

Bpecicatioa of Lettera Patent.

Application led February S515, 11.952., Serial No. 680,180.

To all whom 'it 'may cofwem:

Be it known that I, WILLIAM Monnisorz, a citizen of the United States, residing Des Moines, in the county of Polk and Staf" of Iowa, have invented certain new and usew ful Improvements in Electrolytic Reetitiers, of which the following is a specification.

This invention is an asymmetric electro-l lytic cell. for rectifying alternating electric' currents.

In my U. S. application for Letters Pati- I have described and claimed. an asymmetric cell having an anode of bismuth andan electrolyte of a chromate, phosphate or bicarbonate solution. The present invention is specific improvement thereon, in that an\anode is employed consisting of an alloy of bismuth and an element of the periodic sulfur group having an atomic weight higher than that of sulfur, to Wit tellurium or selenium.

The anode preferably consists of a cast tively small amount of tellurium, one per cen or less of tellurium giving a casting which is fine-grained, densey and strong. The cathode may be a rod or plate of carbon or lead. The electrolyte is preferably a Solution of a chromium-oxygen compound, for example potassium chroniate or dichromate. A solution ofan alkali-metal phosphate or bicarbonate, or of both a chromate and phos phate 'or bicarbonate, or one of the solutions heretofore used with aluminum anodes, may also be employed. The solution may be neutral or somewhat acid or alkaline. For high current-densities a strong solution is preferably employed..

The small amount of tellurum or selenium ailoyed'with the bismuth does not notie .bly impair or affect its action as an asyinznetrio electrode. When an anode of *he alloy is used in a chromate solution, it apparently becomes coated with a permanent adherent film of bismuth chromate, which is of high resistivity and is substantially insoluble in the solution, being one of the most insoluble compounds known.

The accompanying drawing illustrates the described rectifier, the figure being a trans' verse vertical section through the cell and Patented Apr. 9, 1912,.V

electrolyte, the electrodes being shown in elevation.

I claim: 1

l. In an electrolytic rectilier, an anode of bismuth alloyed with an element of the perioclic sultun. group having a higher atomic weight thanjsult'ur, an electrolyte capable of reacting on bismuth to give an asymmetric lilm, and a cathode.

2. In an eleetrelyticrectilier, an anode of bismuth alloyed with tellurium, an electrolyte capable o/reacting on bismuth to give an asymmetric film, and a cathode;

3. In an electrolytic rectilier, an anode of bismuth alloyed with an element of the periodic sulfur group having a higher atomic weight than sulfur, an electrolyte containing a soluble chromate and a cathode.

4. In an electrolytic rectifier, an anode of bismuth alloyed with tellurium, an electrolyte containing a soluble chromate, and a cathode.

'In testimony' whereof I affix my signature in presence of two Witnesses.

`WILLIAM MORRISON.

Nitnessesz EUGENE A. BYRNES, N. P. LEONARD, 

